Study of a Clayey Soil Used in the Fabrication of Red Ceramics in Campos Dos Goytacazes, Brazil

Abstract

In the municipal area of Campos dos Goytacazes, the largest city in the northern region of the state of Rio de Janeiro, southeast of Brazil, there is a clay ceramic industrial pole comprising more than one hundred companies dedicated to the production of bricks, roofing tiles and structural blocks for civil construction. Currently, an estimated production of almost one billion pieces a year attends not only the state of Rio de Janeiro but also the neighbor states of Minas Gerais and Espírito Santo. In this work the characteristics and technical properties of the precursor clayey soil used by one of the leading local industry was studied. The initial characterization was performed by means of granulometric test, based on sieving and sedimentation methods, that allowed the separation of the material in its clay, silt and sand fractions. These fractions were chemically analyzed to evaluate the predominance of oxide content. The fluidity and plasticity limits as well as the apparent density were measured for clay bodies according to the standards. After sintering clay bodies at 700 and 900°C the ceramic technical properties of linear shrinkage, water absorption, apparent density and flexural strength were calculated following the norms. The results indicated that the precursor clay in Campos dos Goytacazes could be used for bricks but need to be incorporated with fluxing compounds to attend the requirements for structural blocks and roofing tiles.